I recently and mostly-randomly came into possession of a
goddamn fantastic ruleset for modern (2001-2010) skirmish wargaming called Skirmish Sangin. It's designed around in-depth action at the squad, or even fire-team, level. In essence, that means if you're running a NATO/ISAF country, you need between 4-10 minis. Total. If you're running Insurgents, it's something like 6-12 minis needed. And a 4 v 4-mini game is perfectly cromulent. In practical terms, that means if you're buying minis from Empress or Eureka, you can get a force up and online for ~$25 including shipping.
The game is similar to the old GW Mordheim or Necromunda games, in that you develop a quick statline for each of your troops, and in the campaign system they can improve skills as you continue playing. Overall game is a d100 task resolution system, with occasional d6 or Xd10 (mostly for damage, this). Take stat, apply positive or negative modifiers to stat, roll under. An M4 that hits the target does 2d10 damage, if your character has armor (usually 1d10+4) roll that and the remaining damage is your cumulative Wound Level. A Wound Level of 13+ is a kill. Wounded soldiers take penalties depending on Level, and also impose morale penalties on nearby friendlies (screaming and bleeding). It also does a really impressive job of creating the "feel" of modern combat; for example it's the first game I've ever seen where if the NATO forces incur a casualty, they receive bonus Victory Points for successfully evacuating the casualty instead of leaving them to bleed out and die.
If anyone is interested, PM me and I'll send a copy of the PDF to you. I happen to have gotten a half-dozen 28mm Taliban for a secret Santa gift last year, so I'm jumping in because why the hell not?